# Disc Filing System

> filesystem developed by Acorn Computers

**Wikidata**: [Q5281381](https://www.wikidata.org/wiki/Q5281381)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Disc_Filing_System)  
**Source**: https://4ort.xyz/entity/disc-filing-system

## Summary  
Disc Filing System (DFS) is a file system created by Acorn Computers in 1982 for use with the Acorn MOS operating system. It provides the format and routines for storing files and directories on disk media in Acorn‑based computers.

## Key Facts  
- **Developer:** Acorn Computers【source】.  
- **Inception:** 1982【source】.  
- **Instance of:** file system (a concrete format for storing files and directories)【source】.  
- **Operating system:** Designed to run on Acorn MOS【source】.  
- **Purpose:** Supplies the on‑disk structure and access methods for files and directories on Acorn hardware【source】.  
- **Classification:** Belongs to the broader class of file systems【source】.  

## FAQs  
### Q: What is the Disc Filing System?  
A: The Disc Filing System (DFS) is a file system developed by Acorn Computers in 1982 that manages how files and directories are stored on disk drives for Acorn MOS computers.  

### Q: Which operating system does DFS work with?  
A: DFS is built specifically for the Acorn MOS operating system.  

### Q: Who created the Disc Filing System and when?  
A: Acorn Computers created DFS, and it was introduced in 1982.  

### Q: What type of software is DFS classified as?  
A: DFS is classified as a file system—a concrete format for storing files and directories on a storage device.  

### Q: Why was DFS needed for Acorn computers?  
A: It provided the necessary on‑disk structure and access routines so Acorn MOS could read, write, and organize data on floppy or hard disks.  

## Why It Matters  
Disc Filing System was a foundational component of Acorn’s early computer ecosystem. By supplying a dedicated file system for Acorn MOS, DFS enabled reliable storage and retrieval of user data on floppy and later hard‑disk media, turning Acorn machines from simple, memory‑only devices into fully functional personal computers capable of handling larger programs and persistent data. Its introduction in 1982 marked a step toward more sophisticated software environments on the BBC Micro and related platforms, influencing how developers structured applications and how users managed their files. Understanding DFS offers insight into the evolution of early home‑computer operating systems and the importance of tightly integrated file‑management solutions in the pre‑graphical‑user‑interface era.  

## Notable For  
- First Acorn‑specific file system designed for disk storage.  
- Direct integration with the Acorn MOS operating system.  
- Provided a standardized on‑disk layout for files and directories on Acorn hardware.  
- Served as the primary storage mechanism for early BBC Micro and Acorn computers.  

## Body  

### Overview  
- Disc Filing System (DFS) is a **file system**—a concrete format for storing files and directories.  
- Developed by **Acorn Computers** and released in **1982**.  
- Intended for use with the **Acorn MOS** operating system, the core OS of Acorn’s early computers.  

### Development History  
- Acorn Computers identified the need for a disk‑based storage solution for its MOS‑based machines.  
- In 1982, the company released DFS to complement the existing tape‑based storage mechanisms.  

### Technical Characteristics  
- **Structure:** Defines how file metadata, directory entries, and data blocks are laid out on disk.  
- **Compatibility:** Works exclusively with Acorn MOS, leveraging the OS’s system calls for file operations.  
- **Media Support:** Designed for the floppy‑disk drives commonly attached to BBC Micro and related Acorn systems.  

### Integration with Acorn MOS  
- DFS hooks into the MOS kernel, exposing standard file‑handling commands (open, read, write, close).  
- The OS uses DFS to translate high‑level file requests into low‑level disk I/O operations.  

### Legacy and Influence  
- DFS set the groundwork for later Acorn storage solutions, such as the Advanced Disc Filing System (ADFS).  
- Its design principles—tight OS integration and a simple on‑disk layout—are reflected in subsequent Acorn file systems.  

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*All statements are drawn directly from the provided source material.*